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Antigen, Streptococcus pneumoniae

S. pneumoniae Urinary Antigen, Ag, strep, pneumonia, Streptococcus pneumoniae Antigen, St. pneumoniae Antigen

Test Codes

EPIC: LAB5471

Department

Microbiology

Specimen Collection Criteria

Collect: Random urine in a sterile collection cup or Gray-top Boric Acid urine tube. (Minimum: 3.0 mL)

Physician Office/Draw Specimen Preparation

Urine: Maintain specimen refrigerated (2-8°C or 36-46°F) prior to courier transport. (Minimum: 3.0 mL)

Preparation for Courier Transport

Transport:

Urine specimen in a sterile collection cup or Gray-top urine tube, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

• Specimens other than urine.
• Preservatives other than boric acid.

Storage

Specimen Stability for Testing:

Room Temperature (20-25°C or 68-77°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 14 days

Specimen Storage in Department Prior to Disposal:

Urine: Refrigerated (2-8°C or 36-46°F): 4 days 

Laboratory

Dearborn Microbiology Laboratory
Taylor, Trenton and Wayne sent to Dearborn Microbiology Laboratory for testing.

Royal Oak Microbiology Laboratory
Farmington Hills and Grosse Pointe sent to Royal Oak Microbiology Laboratory for testing.

Troy Microbiology Laboratory

Performed

Sunday – Saturday, 24 hours a day.
STAT results available within 1 hour of receipt in the Microbiology Laboratory.
Results available within 24 hours.

Reference Range

Negative for Streptococcus pneumoniae Antigen.

Test Methodology

Immunochromatographic Assay.

Interpretation

A negative antigen result does not exclude infection with S. pneumoniae. Therefore, the diagnosis of pneumococcal disease should not be based solely upon the results of this test. The sensitivity of this test with urine is 80% in patients with positive blood cultures and 52% in patients with positive sputum cultures but the specificity is high (1). Other parameters including clinical findings, culture and other antigen detection methods should be used to make an accurate diagnosis.

This test has not been evaluated on patients taking antibiotics for greater than 24 hours or on patients who have recently completed antibiotic therapy.

False positive results within 5 days following S. pneumoniae vaccination. 

The accuracy of this test in urine has not been proven in children less than 6 years old.

Clinical Utility

This test can assist in the diagnosis of pneumococcal pneumonia.

Clinical Disease

S. pneumoniae is the leading cause of community-acquired pneumonia. Mortality rates can reach 30% depending upon bacteremia, age and the presence of underlying diseases. Untreated S. pneumoniae infections can lead to bacteremia, meningitis, pericarditis, empyema, purpura fulminans, endocarditis and/or arthritis.

Pneumococcal meningitis, a condition that frequently leads to permanent brain damage or death, can occur as a complication of other pneumococcal infection or may arise spontaneously without any preceding illness. Twenty to thirty percent of all pneumococcal meningitis patients will die, often despite several days of appropriate antibiotic treatment. Mortality is even higher among very young and very old patients.

S. pneumoniae is the most common bacterial cause of acute otitis media and of invasive bacterial infections in children. Pneumococci are also a frequent cause of sinusitis and bacterial pneumonia. Since the introduction of widespread Haemophilus influenzae type b (Hib) conjugate vaccination, pneumococci have become one of the two most common causes of bacterial meningitis in young children (1).

Epidemiology

Pneumococci are ubiquitous; many persons have colonization of the upper respiratory tract. Among young children who acquire a new pneumococcal serotype in the nasopharynx, illness (usually otitis media) occurs in 15%, generally within 1 month of acquiring the new serotype. Illness seldom is associated with preceding prolonged carriage. Viral upper respiratory tract infections, including influenza, predispose patients to pneumococcal diseases. These infections are most common in infants, young children, and older persons. Disease occurrence increases in persons with congenital or acquired immunodeficiency involving humoral immunity (e.g., agammaglobulinemia), including HIV infection; those with absent or deficient splenic function, including sickle cell disease, congenital asplenia, and following surgical splenectomy; nephrotic syndrome; chronic renal failure; organ transplantation; diabetes mellitus; chronic pulmonary disease; or congestive heart failure.

Incubation Period

Varies by type of infection and can be as short as 1 to 3 days (1).

Transmission

Transmission is from person to person, presumably by respiratory droplet contact (1). Patients are infectious as long as the organism is present in respiratory tract secretions. Patients are usually not infectious 24 hours after effective antimicrobial therapy is begun (1).

Reference

1. Murdoch, D.R. et al. 2001. Evaluation of rapid immunochromatographic test for detection of Streptococcus pneumoniae antigen in urine samples from adults with community-acquired pneumonia J. Clinical Microbiology. 39:3495-3498.
2. Spellerberg, B., and C. Brandt. 2015. Streptococcus. In: Jorgensen, J.H. et. al. (eds.). Manual of Clinical Microbiology. 11^th edition. ASM Press. Washington, D.C.

CPT Codes

87449

Contacts

Last Updated

10/9/2023